This invention relates to tufting machines and is more particularly concerned with an apparatus and method for producing tufts from different yarns in common longitudinal rows.
In the past, the tufting industry has long sought for an easy and efficient way of producing tufts from different yarn in selected single, longitudinal rows. Thus, stop needle machines were produced in which the needles of the tufting machine were aligned longitudinally but were selectively operated so that one needle sewed a portion of a longitudinal row while the other was stopped. Such machines were impractical for high speed tufting and were expensive to build, maintain and program.
Another form of prior art tufting machine which could produce tufts of different characteristics was the machine which had "cut-loop loopers." Such a machine had a cut pile looper with a spring clip which enabled the yarn feed mechanism to control, by the amount of yarn feed to the needle, whether the yarn formed a cut pile or a loop pile. The successive tufts in a longitudinal row, however, had to be from a single yarn and precluded multicolor tufts from different yarns in a single row.
Another form of providing a multicolored appearance in a tufted product was by producing high cut pile tufts in one row to overlie low loop pile in an adjacent row.
Still another method of tufting to produce a multicolored pattern involved the use of laterally shiftable front and back needle bars which enabled the needles of one needle bar to be moved so as to cooperate, selectively, with different laterally spaced loopers. All needles were inserted into the backing material for each reciprocation, however, the needles of one needle bar were always staggered with respect to the needles of the other needle bar and the front loopers were staggered with respect to the rear loopers. In such prior art machines, the shift of one needle bar with respect to the other, had to be a lateral distance equal to at least two gauges of tufting. U.S. Pat. No. 4,366,761 illustrates such a machine. The shifting by two gauges causes the accumulation of excessive yarns in the back stitches. By having to shift one needle bar two gauges with respect to the other, this prevented making a continuous diagonal row of tufts, using a selected yarn or yarns. Therefore, a diagonal line of tufting in a tufted product has had to appear as broken lines, formed by a succession of spaced discrete pin dots.